Consumer habits with respect to food preparation have changed dramatically and perhaps irrevocably over the past twenty years. The days of a homemaker routinely making products such as breads, cakes, cookies, muffins, or pancakes "from scratch" within the home are substantially gone. Changing lifestyles for both consumers and preparers of food have resulted in a situation where very little time is available for cooks within the home to regularly make baked goods from fundamental ingredients, such as flour, water, sugar, baking powder and baking soda.
Additionally, consumers have been regularly exposed to foods professionally prepared by others, having particular textures and flavors of consistent quality. This exposure has occurred as a result of eating out in restaurants and bringing food into the home that is fully prepared. This food is not limited to "fast food" but includes meals fully prepared by restaurants for "take out" or food prepared by caterers. Over time, consumers have acquired standards for textures of bread, cakes, cookies and pancakes, which are not easily reproducible time after time within the home. Home made food products which do not meet these particular standards are regarded as unsatisfactory. The cook in the home feels that he or she is inadequate because of an inability to reproduce a particular texture, mouth-feel, and flavor for a food product each and every time the food is prepared.
In response to these changes in consumer habits and expectations, manufacturers of products such as breads, cakes, cookies and pancakes have prepared for sale, intermediate forms of these products. The intermediate forms have included products such as doughs and batters. These intermediate forms of food products have been offered with a goal of satisfying a consumer's need for a freshly baked foodstuff such as muffins or cake while expending a minimum amount of time for food preparation with minimum risk of failure. It has also been hoped that by providing the batters or doughs, a consistent, predictable organoleptic quality can be achieved each time the batters or doughs are cooked or baked to make the edible foodstuff.
Manufacturers have encountered several significant problems in providing these intermediate products such as batters or doughs. One problem has been degradation of the intermediate product in storage due to undesirable chemical reactions. Doughs such as bread dough and batters such as cake batter are complicated chemical systems. In a case of yeast leavened bread dough, the dough is not only a complicated chemical system but is also a complicated biological system because of living yeast cells within the dough. Storage of yeast leavened dough or batter at refrigerated temperatures has resulted in premature leavening of the batter or dough which has produced an undesirable baked good.
One type of dough product is a chemically-leavened dough stored at refrigeration temperatures. Currently, refrigerated dough products are manufactured, and packaged in cardboard cans or tubes. The cans are filled with dough to about 80% capacity by volume, prior to proofing the dough. The cardboard cans comprise an annular sidewall and opposing metal ends. The metal ends of the cans are forced into the annular sidewall of each of the cans.
The cans with the product contained therein are then proofed at 32.2.degree. C. for several hours to allow release of carbon dioxide generated by a leavening reaction. The dough may be chemically leavened or leavened by temperature sensitive yeast cells. The atmosphere created by leavening is anaerobic within the can and allows for expansion of the dough so that the dough pushes against the metal ends. A continuous release of carbon dioxide through tiny fissures or vents within the can generates internal can pressures of up to 0.7 to 1.7 atm which the can must sustain throughout storage. The can in which dough is stored must be strong enough to prevent dough generated pressure from breaking open the can.
The internal pressure generated within the can by dough leavening reactions prevents further expansion of the carbon dioxide gas from breaking open the can. The internal pressure also prevents further expansion of carbon dioxide gas bubbles within the dough and thus stops the leavening reaction. In chemically leavened refrigerated dough products, leavening agents such as leavening acids and sodium bicarbonate are in direct contact with each other. Small bubbles of carbon dioxide are formed and released during their manufacture and storage. If these doughs are packaged in containers which are not subject to pressurization, complete release of carbon dioxide within the dough occurs and the container may literally explode. Moreover, if the carbon dioxide is liberated from the container during storage, destroying equilibrium within the container, product quality suffers.
The pH of the stored dough is elevated to a range between 6.5-7.5 because of the partial completion of the leavening reaction. This near neutral pH is ideal for microbial growth. Therefore, the microbial safety of the products depends upon a strict control of water activity of the product and maintenance of the anaerobic atmosphere within the can.
In order to reduce the risk of elevated batter pH during storage, actions have been taken to separate batter fractions and to sterilize dough ingredients. The Moran et al. U.S. Pat. No. 3,970,763 issuing Jul. 20, 1976, describes a cake batter which is prepared by mixing separate aqueous and fat phases. Each of the phases has been heat treated. The aqueous phase is aerated prior to heat treatment. The batter is packaged and stored at refrigerated temperatures.
The Keller et al. U.S. Pat. No. 2,870,026 issuing Jan. 20, 1959, describes a refrigerated batter product. The method includes a step of heating a prepared batter at a temperature within a range of 62.8.degree. to 85.degree. C. for about 10 seconds to 30 minutes. The batter is then cooled to a refrigerated temperature. The cooled batter is whipped in order to incorporate gas bubbles within the batter.
One approach to controlling and slowing the leavening reaction is an orchestrated exposure of ingredients to each other. U.S. Pat. No. 2,982,662 issuing May 2, 1961, the Cochran et al. patent, describes a procedure for preventing collapse of water and fat emulsion of a batter during storage. The method includes a step of preparing a batter than includes dicalcium phosphate dihydrate as a sole acidic leavening agent. Any emulsifier such as a lower hydroxy carboxylic acid fatty acid ester of an edible polyhydric alcohol having 3-6 hydroxyl groups is also added as an emulsifier. All ingredients of the batter are mixed together to form a mixture which is homogenized and stored at a refrigeration temperature for a period of about three days. Soda may then be added for leavening. The batter is then stored at refrigeration temperatures until it is used to bake a product.
The Savre et al. U.S. Pat. No. 3,433,646 issuing Mar. 18, 1969, describes a method for making a batter for storage at refrigeration temperatures. The method includes a step of forming an aqueous solution that contains chemical leavening agents and part of the total water content of the batter. The solution is mixed so that the leavening agents react with each other and liberate a portion of the available carbon dioxide. The non-liquid batter forming ingredients are added to the aqueous solution to form a mixture which is blended with the remaining water and mixed to form a homogeneous batter. Residual leavening ingredients in the batter do not react with each other until a temperature of about 60.degree. C. is reached.
One other approach to controlling the leavening reaction during storage is to shield leavening reactants from each other. The Hans U.S. Pat. No. 3,620,763, issuing Nov. 16, 1971, describes a batter that is stored in a pressurized container. The batter includes a polysaccharide hydrophilic film-forming agent. This material acts as a humectant.
The Fehr Jr. et al. U.S. Pat. No. 3,649,304 issuing Mar. 14, 1972, describes a refrigerated batter. The refrigerated batter is made by congealing an acid-leavening agent in a water-gelatin solution. A basic leavener is added to the remaining batter mixture and carbon dioxide is evolved. The congealed acid leavener is added to the batter that includes the basic leavener. Both leaveners react to produce carbon dioxide which displaces oxygen in the container. The container is then subjected to a temperature which is a refrigeration temperature.
Currently, encapsulated sodium bicarbonate is being used in the manufacture of refrigerated doughs. However, the capsules formed with the sodium bicarbonate core function more as processing aids to prevent release of carbon dioxide during the manufacturing process than as a leavening agent. Current levels of encapsulation and quality of capsules and microcapsules provide some degree of shielding and may prevent chemical reaction with leavening acids for a few hours to up to a few days.
The existing capsules do not provide protection through the complete duration of the storage of such products which is around two to three months. Therefore, the cans need to be pressurized to provide adequate shelf life and final finished product quality.
The Selenke U.S. Pat. No. 4,022,917 issuing May 10, 1977, describes a batter that is made with particles of an alkaline leavening agent. These particles are encapsulated in a water-insoluble coating which is added to the batter. The alkaline leavening agent is dispersed in the batter at a cooking temperature and is released at a temperature of at least about 60.degree. C.
PCT Application PCT/US98/15075, which published Feb. 4, 1999, describes a spoonable batter that is stable at refrigeration temperature for at least about 75 days. The batter has a water activity of about 0.81 to 0.92. The batter contains 20 to 30 percent sugar.
Another problem that must be solved in order to make a satisfactory dough or batter product is maintenance of integrity of the dough or batter structure during and after proofing and baked product structure. The Fioriti et al. U.S. Pat. No. 3,975,550 issuing Aug. 17, 1976, describes a batter which is deformable at a temperature as low as -17.8.degree. C. The batter includes ingredients such as eggs, oil, sugar, flour, a leavening agent and a low molecular weight alcohol, glycol or polyol having a freezing point below -17.8.degree. C.
The Aliberto et al. U.S. Pat. No. 4,504,510 issuing Mar. 12, 1985, describes a pancake batter that can be stored in either the refrigerator or a freezer. The pancake batter includes an emulsified plastic shortening capable of forming stabilized air cells. Emulsifiers include mono- and diglycerides and propylene glycol esters of fats and fatty acids. The pancake batter is mechanically aerated and as a consequence of the emulsified plastic shortening presence, air cells formed during aeration remain in the batter over extended periods of time.
The Petrizzelli U.S. Pat. No. 4,904,493, and the Seewi et al. U.S. Pat. No. 5,178,893, describe doughs that can be stored. The doughs have a water content that is not more than 16 percent. The doughs are also made with flour that has been inactivated with respect to enzyme activity.
A European Patent Application, EP 0 868 850 A1, describes shelf-stable cake dough. The dough includes glycerol and a high concentration of sugar in order to reduce water activity. The dough also includes a flour treated to inactivate enzyme activity and an encapsulated leavening system.